# Capabilities Overview > Capabilities give an agent tools, system prompt fragments, and execution features. Index of every built-in capability. Source: Capabilities are modular units that extend what an agent can do. Each capability can contribute: * **Tools**: callable functions the agent can invoke during conversations * **System prompt additions**: context and instructions prepended to the agent’s prompt * **Features**: UI elements unlocked when the capability is active (e.g., Workspace tab) Agents compose capabilities; enable only what you need. ## Capability Reference Every capability a production deployment offers, with the number of tools it adds by default. Rows marked **dev-only** are registered only at the `dev` deployment grade. A `FEATURE_*` variable identifies a [rollout grade override](https://everruns.com/docs/sre/environment-variables/#feature-rollout-grades); organisation enrolment also applies before assigning or using gated capabilities. ### Core Fundamental capabilities for file operations, command execution, web access, session management, time awareness, task tracking, scheduling, and agent coordination. | Capability | ID | Tools | | ---------------------------------------------------------------------------------------------------- | --------------------------- | ----------------------------------------------------------- | | [File System](https://everruns.com/docs/capabilities/file-system/) | `session_file_system` | 10 | | [Bashkit Shell](https://everruns.com/docs/capabilities/bashkit-shell/) | `bashkit_shell` | 1 | | [Tools in Shell](https://everruns.com/docs/capabilities/tools-in-shell/) | `tools_in_shell` | 1 (`tools`, hidden from the model; it is the shell command) | | [Host Shell](https://everruns.com/docs/capabilities/host-shell/) | `host_shell` | 1 (Framework-only) | | [Session](https://everruns.com/docs/capabilities/session/) | `session` | 2 | | [Storage](https://everruns.com/docs/capabilities/session-storage/) | `session_storage` | 2 | | [Web Fetch](https://everruns.com/docs/capabilities/web-fetch/) | `web_fetch` | 1 | | [Web Search](https://everruns.com/docs/capabilities/web-search/) | `web_search` | 1 | | [Current Time](https://everruns.com/docs/capabilities/current-time/) | `current_time` | 1 | | [Message Metadata](https://everruns.com/docs/capabilities/message-metadata/) | `message_metadata` | 0 | | [Ask User](https://everruns.com/docs/capabilities/ask-user/) | `ask_user` | 1 | | [Task Management](https://everruns.com/docs/capabilities/task-management/) | `stateless_todo_list` | 1 | | [Schedules](https://everruns.com/docs/capabilities/session-schedules/) | `session_schedule` | 3 | | [Auto-Continue After Usage Limit](https://everruns.com/docs/capabilities/usage-limit-auto-continue/) | `usage_limit_auto_continue` | 0 | | [AGENTS.md](https://everruns.com/docs/capabilities/agent-instructions/) | `agent_instructions` | 0 | | [Agent Skills](https://everruns.com/docs/capabilities/agent-skills/) | `skills` | 2; `FEATURE_SKILLS` grade | | Channel Thread Context | `channel_context` | 0 | | System Commands | `system_commands` | 0 | ### Orchestration Delegating work to other sessions and running it in the background. | Capability | ID | Tools | | ------------------------------------------------------------------------------------ | ---------------------- | --------------------------------------------------------- | | [Sub Agents](https://everruns.com/docs/capabilities/sub-agents/) | `subagents` | 0 (contributes the `spawn_agent` delegation target) | | Session Tasks | `session_tasks` | 5 | | Background Execution | `background_execution` | 1 | | [Agent Handoff](https://everruns.com/docs/capabilities/agent-handoff/) | `agent_handoff` | 0 (contributes the `agent` `spawn_agent` target) | | [A2A Agent Delegation](https://everruns.com/docs/capabilities/a2a-agent-delegation/) | `a2a_agent_delegation` | 0 (contributes the `external_a2a` `spawn_agent` target) | | AG-UI Agent Delegation | `ag_ui_delegation` | 0 (contributes the `external_ag_ui` `spawn_agent` target) | | [Coordination](https://everruns.com/docs/framework/coordination/) | `coordination` | 5 | ### Sandboxes Cloud and container sandbox environments for isolated code execution. | Capability | ID | Tools | | ------------------------------------------------------------------------------ | ------------------- | ------------------------------------------------------------------- | | Managed Environment | `session_sandbox` | 6 | | [Sandbox Fleet](https://everruns.com/docs/capabilities/sandbox-fleet/) | `sandbox_fleet` | 8 | | [Daytona](https://everruns.com/docs/capabilities/daytona/) | `daytona` | 10 | | [E2B](https://everruns.com/docs/capabilities/e2b/) | `e2b` | 6 | | Deno Sandboxes | `deno` | 6 | | [Container Sandbox](https://everruns.com/docs/capabilities/container-sandbox/) | `container_sandbox` | 8 (needs `FEATURE_CONTAINER_SANDBOX=prod`) | | [Docker Container](https://everruns.com/docs/capabilities/docker/) | `docker_container` | 5 (off by default, needs `FEATURE_DOCKER_CAPABILITY` rollout grade) | ### Browser Browser automation and web interaction capabilities. | Capability | ID | Tools | | -------------------------------------------------------------------- | -------------- | ------------------------------------------- | | [Browserless](https://everruns.com/docs/capabilities/browserless/) | `browserless` | 7 | | [Browser Use](https://everruns.com/docs/capabilities/browser-use/) | `browser_use` | 1; `FEATURE_BROWSERLESS_BROWSER_USE` grade | | [Computer Use](https://everruns.com/docs/capabilities/computer-use/) | `computer_use` | 1; `FEATURE_BROWSERLESS_COMPUTER_USE` grade | ### Data and knowledge Structured data, knowledge retrieval, and memory. | Capability | ID | Tools | | -------------------------------------------------------------------------------------- | ----------------------- | ------------------------------------------------------------------------ | | [SQL Database](https://everruns.com/docs/capabilities/sql-database/) | `session_sql_database` | 3 | | [Retrieval Citations](https://everruns.com/docs/capabilities/citation-retrieval/) | `citation_retrieval` | 0 | | [Citation Verification](https://everruns.com/docs/capabilities/citation-verification/) | `citation_verification` | 0 | | [Data Knowledge](https://everruns.com/docs/capabilities/data-knowledge/) | `data_knowledge` | 0 | | [Knowledge Base](https://everruns.com/docs/capabilities/knowledge-base/) | `knowledge_base` | 1; `FEATURE_KNOWLEDGE` grade | | [Knowledge Index](https://everruns.com/docs/capabilities/knowledge-index/) | `knowledge_index` | 0 (adds `search_index` when `indexes` is set); `FEATURE_KNOWLEDGE` grade | | [Memory](https://everruns.com/docs/capabilities/memory/) | `memory` | 0; `FEATURE_MEMORY` grade | ### Media Image generation and editing workflows. | Capability | ID | Tools | | ------------------------------------------------------------------------------------------ | --------------- | ----- | | [OpenAI Image Generation](https://everruns.com/docs/capabilities/openai-image-generation/) | `gpt_image_gen` | 2 | ### Models and provider tools Provider-executed tools and model selection. | Capability | ID | Tools | | ------------------------------------------------------------------------------------------ | --------------------------- | ------------------------------------ | | [OpenAI Server Tools](https://everruns.com/docs/capabilities/openai-server-tools/) | `openai_server_tools` | 0 | | [OpenRouter Server Tools](https://everruns.com/docs/capabilities/openrouter-server-tools/) | `openrouter_server_tools` | 0 | | Model Scout | `model_scout` | 0 | | OpenRouter Workspace | `openrouter_workspace` | 2 | | OpenAI Agents API Runtime | `openai_agents_api_runtime` | 0; `FEATURE_OPENAI_AGENTS_API` grade | ### Integrations External-service capabilities and blueprint-backed workflows. | Capability | ID | Tools | | ------------------------------------------------------------------------------------ | -------------------- | ------------------------------------ | | [GitHub](https://everruns.com/docs/capabilities/github/) | `github` | 5 (6 with `allow_pull_requests`) | | [GitHub Scout](https://everruns.com/docs/capabilities/github-scout/) | `github_scout` | 0 | | [Slack](https://everruns.com/docs/capabilities/slack/) | `slack` | 4 | | Cursor | `cursor` | 9 | | [Agentic Resource Discovery](https://everruns.com/docs/integrations/ard/) | `resource_discovery` | 3 | | [AgentID Sign-In](https://everruns.com/docs/integrations/agentid/) | `agentid` | 1 | | [Brave Search](https://everruns.com/docs/integrations/brave-search/) | `brave_search` | 1 | | [DuckDuckGo](https://everruns.com/docs/integrations/duckduckgo/) | `duckduckgo` | 1 | | [Parallel Search and Fetch](https://everruns.com/docs/integrations/parallel/) | `parallel_search` | 0 (2 hosted MCP tools from Parallel) | | [Jev Decisions](https://everruns.com/docs/integrations/typesafe/) | `jev` | 1 | | [User MCP Servers](https://everruns.com/docs/capabilities/user-mcp-servers/) | `user_mcp` | 6 (only with `manage` on) | | [Poppy Personal Agent](https://everruns.com/docs/capabilities/poppy-personal-agent/) | `poppy_client` | 5 | ### Platform Agent self-management and platform control. | Capability | ID | Tools | | ------------------------------------------------------------ | ---------- | ----- | | [Platform](https://everruns.com/docs/capabilities/platform/) | `platform` | 3 | ### Generative UI Structured UI the agent renders in the chat. | Capability | ID | Tools | | ---------- | -------- | ----- | | OpenUI | `openui` | 0 | | A2UI | `a2ui` | 0 | ### Optimization Performance and cost optimization for LLM interactions. | Capability | ID | Tools | | ---------------------------------------------------------------------------------------- | --------------------- | ----------------------------------------------------------- | | [Infinity Context](https://everruns.com/docs/capabilities/infinity-context/) | `infinity_context` | 1 | | [Context Compaction](https://everruns.com/docs/advanced/compaction/) | `compaction` | 0 | | [Auto Tool Search](https://everruns.com/docs/capabilities/tool-search/#auto-tool-search) | `auto_tool_search` | 0 (adds `tool_search` on models without native tool search) | | [OpenAI Tool Search](https://everruns.com/docs/capabilities/tool-search/#hosted-openai) | `openai_tool_search` | 0 | | [Claude Tool Search](https://everruns.com/docs/capabilities/tool-search/#hosted-claude) | `claude_tool_search` | 0 | | [Tool Search](https://everruns.com/docs/capabilities/tool-search/#client-side) | `tool_search` | 1 | | [Budgeting](https://everruns.com/docs/capabilities/budgeting/) | `budgeting` | 1 | | [Self-Budget](https://everruns.com/docs/capabilities/self-budget/) | `self_budget` | 0 | | [Parallel Tool Calls](https://everruns.com/docs/capabilities/parallel-tool-calls/) | `parallel_tool_calls` | 0 | | Native Async Tools | `native_async_tools` | 0 | | [Prompt Caching](https://everruns.com/docs/capabilities/prompt-caching/) | `prompt_caching` | 0 | ### Safety Streaming-output guardrails and runtime safety nets. | Capability | ID | Tools | | ------------------------------------------------------------------------------------------ | ------------------------- | ----- | | [Prompt Canary Guardrail](https://everruns.com/docs/capabilities/prompt-canary-guardrail/) | `prompt_canary_guardrail` | 0 | | [Tool Call Repair](https://everruns.com/docs/capabilities/tool-call-repair/) | `tool_call_repair` | 0 | | [Output Truncation](https://everruns.com/docs/capabilities/output-truncation/) | `output_truncation` | 0 | | [Guardrails](https://everruns.com/docs/capabilities/guardrails/) | `guardrails` | 0 | | [Tool Approval](https://everruns.com/docs/capabilities/tool-approval/) | `tool_approval` | 0 | | [Dry Run](https://everruns.com/docs/capabilities/dry-run/) | `dry_run` | 0 | | Progress Guard | `progress_guard` | 0 | | [Soft Approval](https://everruns.com/docs/capabilities/soft-approval/) | `soft_approval` | 3 | | [Tool Loop Detection](https://everruns.com/docs/capabilities/loop-detection/) | `loop_detection` | 0 | The [`guardrails`](https://everruns.com/docs/capabilities/guardrails/) capability runs config-driven checks over model output and tool activity, blocking or logging per check. Checks can be deterministic (regex, blocklist, tool-call patterns) or model-backed, an `llm_judge` policy or a `moderation` decision, plus delegation to an external guardrail over scoped MCP. Each check binds a rule to a stage (`output`, `tool_use`, `tool_output`) with an `on_fail` of `block` or `log`; model-backed and MCP checks send a bounded excerpt off the sync path and fail open. Use advisory mode and the `POST /v1/capabilities/guardrails/dry-run` endpoint to tune against false positives before enforcing. For ready-made starting points, list the gallery at `GET /v1/capabilities/guardrails/examples`, each preset carries a `data_egress` signal (`none` vs. `utility_llm`), and drop a preset’s `config` into the agent’s `guardrails` capability config. ### Automation Run shell commands at lifecycle and tool events. Block, mutate, or audit agent actions from outside the model. | Capability | ID | Tools | | ---------------------------------------------------------------- | ------------ | ----- | | [User Hooks](https://everruns.com/docs/capabilities/user-hooks/) | `user_hooks` | 0 | Harnesses also compose capabilities that are settings rather than features: Human Intent, BTW, Error Disclosure, and Tool Output Persistence and Distillation. The canonical [harness levels](https://everruns.com/docs/features/harnesses/) and [Platform Chat](https://everruns.com/docs/built-ins/harnesses/platform-chat/) harness pages describe them. ## Quick Start ### Enable via API ```bash curl -X POST http://localhost:9300/api/v1/agents \ -H "Content-Type: application/json" \ -d '{ "name": "My Agent", "system_prompt": "You are a helpful assistant.", "capabilities": ["session_file_system", "bashkit_shell", "web_fetch"] }' ``` ### Enable via UI 1. Navigate to the Agent detail page 2. Open the **Capabilities** section 3. Toggle capabilities on/off 4. Reorder with drag handles (order affects system prompt priority) 5. Save ### List available capabilities ```bash curl http://localhost:9300/api/v1/capabilities ``` ### Create a declarative capability Declarative capabilities are persisted capability definitions made from data: system prompt text, scoped MCP servers, text file mounts, and skill packages. They use a public resource ID like `cap_...` and a stable capability reference like `declarative:research_pack`. ```bash curl -X POST http://localhost:9300/api/v1/capabilities \ -H "Content-Type: application/json" \ -d '{ "definition": { "name": "research_pack", "display_name": "Research Pack", "description": "Default research behavior and resources.", "system_prompt": "Prefer primary sources and cite them clearly.", "risk_level": "low" } }' ``` Agents and harnesses can use the canonical reference: ```json { "ref": "declarative:research_pack" } ``` For convenience, agent and harness write APIs also accept the plain unique name when it matches a declarative capability: ```json { "ref": "research_pack" } ``` ## Key Concepts ### Dependencies Some capabilities depend on others. Dependencies are resolved automatically at runtime, you don’t need to manually add them. | Capability | Depends On | | ------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------- | | [Bashkit Shell](https://everruns.com/docs/capabilities/bashkit-shell/) | [File System](https://everruns.com/docs/capabilities/file-system/) | | [Tools in Shell](https://everruns.com/docs/capabilities/tools-in-shell/) | [Bashkit Shell](https://everruns.com/docs/capabilities/bashkit-shell/) | | [Host Shell](https://everruns.com/docs/capabilities/host-shell/) | [File System](https://everruns.com/docs/capabilities/file-system/) | | [Platform](https://everruns.com/docs/capabilities/platform/) | [File System](https://everruns.com/docs/capabilities/file-system/) (when embedded docs are enabled) | | [Agent Skills](https://everruns.com/docs/capabilities/agent-skills/) | [File System](https://everruns.com/docs/capabilities/file-system/) | | [GitHub Scout](https://everruns.com/docs/capabilities/github-scout/) | [Sub Agents](https://everruns.com/docs/capabilities/sub-agents/) | | Managed Environment | [Storage](https://everruns.com/docs/capabilities/session-storage/) | | [Sandbox Fleet](https://everruns.com/docs/capabilities/sandbox-fleet/) | [Storage](https://everruns.com/docs/capabilities/session-storage/) | | [E2B](https://everruns.com/docs/capabilities/e2b/) | [Storage](https://everruns.com/docs/capabilities/session-storage/) | | [Daytona](https://everruns.com/docs/capabilities/daytona/) | [Storage](https://everruns.com/docs/capabilities/session-storage/) | | Deno Sandboxes | Storage | | [Browserless](https://everruns.com/docs/capabilities/browserless/) | [Storage](https://everruns.com/docs/capabilities/session-storage/) | | [Browser Use](https://everruns.com/docs/capabilities/browser-use/) | [Storage](https://everruns.com/docs/capabilities/session-storage/) | | [Computer Use](https://everruns.com/docs/capabilities/computer-use/) | [Storage](https://everruns.com/docs/capabilities/session-storage/) | | [OpenAI Image Generation](https://everruns.com/docs/capabilities/openai-image-generation/) | [File System](https://everruns.com/docs/capabilities/file-system/) | | [Data Knowledge](https://everruns.com/docs/capabilities/data-knowledge/) | [File System](https://everruns.com/docs/capabilities/file-system/) | | [Memory](https://everruns.com/docs/capabilities/memory/) | [File System](https://everruns.com/docs/capabilities/file-system/) | | [Container Sandbox](https://everruns.com/docs/capabilities/container-sandbox/) | [Storage](https://everruns.com/docs/capabilities/session-storage/) | | [A2A Agent Delegation](https://everruns.com/docs/capabilities/a2a-agent-delegation/) | Session Tasks | | AG-UI Agent Delegation | Session Tasks | ### Features Capabilities declare UI features they contribute. The session aggregates features from all active capabilities to decide which UI tabs to render. | Feature | UI Element | Contributed By | | -------------- | ------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | `file_system` | Workspace tab | [File System](https://everruns.com/docs/capabilities/file-system/), [Bashkit Shell](https://everruns.com/docs/capabilities/bashkit-shell/), [Host Shell](https://everruns.com/docs/capabilities/host-shell/) | | `secrets` | Storage tab | [Storage](https://everruns.com/docs/capabilities/session-storage/) | | `key_value` | Storage tab | [Storage](https://everruns.com/docs/capabilities/session-storage/) | | `schedules` | Schedules tab | [Schedules](https://everruns.com/docs/capabilities/session-schedules/) | | `sql_database` | Database tab | [SQL Database](https://everruns.com/docs/capabilities/sql-database/) | | `subagents` | Subagents tab | [Sub Agents](https://everruns.com/docs/capabilities/sub-agents/) | | `citations` | Inline citation chips + Sources strip | [Retrieval Citations](https://everruns.com/docs/capabilities/citation-retrieval/), [Citation Verification](https://everruns.com/docs/capabilities/citation-verification/) | ### Ordering Capabilities are applied in the order configured on the agent. Earlier capabilities’ system prompt additions appear first. Place the most important context-setting capabilities first. ## See Also * [Concepts](https://everruns.com/docs/getting-started/concepts/), how capabilities fit into the Harness → Agent → Session model * [API Reference](https://everruns.com/docs/api/), full API documentation * [MCP Servers](https://everruns.com/docs/features/mcp/), external tool servers as virtual capabilities